kenworth truck fuel cap is aluminum fit for Fuel Tank Accessories. We recommend measuring your fuel tank before buy ,using the photos on the listing to verify sizing. ID of 3.5" and OD of 4". This fuel cap is non locking and for diesel tanks marked ULTRA LOW SULFUR DIESEL and LOW SULFUR DIESEL. the fuel cap is not vented, your fuel tank must be vented. This cap is aluminum and has a 8.0" stainless chain & 6.5" stainless bail.